This invention relates to friction coupling apparatus such as industrial air cooled clutches and brakes. More particularly, the invention relates to fluid motor actuators utilized in the control of such apparatus.
Prior art industrial clutches and brakes of the air-cooled type, including tension brakes, have traditionally employed thin-walled elastomeric actuators, generally of two piece casings comprising mating pairs of diaphragms. Such thin-walled multi-piece elastomeric members have not only been more difficult to install, but have been relatively susceptible to puncture by their support members. The latter has resulted in costly field failures, as the equipment involved is generally quite large, and typically moves massive amounts of material.
Another drawback of the prior art actuators for friction coupling apparatus is a general difficulty of access to the friction members associated therewith. Thus, many of such devices require substantial down time including disassembly of major portions of the equipment to merely change friction linings. Although a few of such devices have incorporated provisions requiring less disassembly, for example swing arms, the latter improvements are still not entirely satisfactory.
Finally, the conventional rotor members associated with prior art actuators have lacked efficient cooling media, most including only fins over their external rotor boundaries. Thus, the prior art has also been deficient in providing pneumatic actuators which are cooled satisfactorily.